Potting resin receives WRAS approval for contact with drinking water

Wevo resins

A two-component potting compound from WEVO-CHEMIE GmbH has now been granted drinking water approval by the internationally recognised Water Regulations Advisory Scheme (WRAS) and can therefore be used in the production of drinking water filters and for protecting electrical and electronic components used in the fields of drinking and process water.

According to Germany’s Federal Statistical Office, each individual in the country consumes around 123 litres of water per day. Maintaining a consistently high-quality water supply is essential and is ensured by carrying out analysis. One of the requirements for materials deployed in the drinking water sector is that they must not alter the drinking water in any way, for example, by contaminating it or changing its smell or taste.

Wevo submitted a two-component, polyurethane-based potting resin for auditing according to the stringent WRAS test procedure. Among other things, the organisation promotes regulations for keeping the UK’s drinking water clean and checks compliance with them. During the evaluation of materials, special focus is placed on the possible release of heavy metals, changes in the taste and smell of the water samples and the prevention of harmful effects on cellular and aquatic organisms.

The polyurethane potting resin made of WEVOPUR 2082 and the hardener WEVONAT 1000 has passed the rigorous tests and is now certified in accordance with BS 6920-1:2000/2014. As a result, the product can be used to manufacture drinking water filters and to protect electrical and electronic components that are in constant contact with drinking water at temperatures of up to 23 °C. Potential applications in the areas of drinking water management and filtration alongside conventional water filters include flow sensors, pump housings and control panels. Other potential application areas are systems and filters for treating process water, such as those used in power stations, the chemical and pharmaceutical industries, in breweries and in the production of juice and wine.

Potting resin provides advantages in processing and use
Compared to the epoxy resins frequently used in the drinking water sector, this polyurethane potting compound offers a range of advantages in processing. The heat generated during processing is less, allowing potting to be carried out in one step without any interruption, also when potting larger volumes. This process is also void-free and safe – even with complex geometries – thanks to the relatively low viscosity of Wevo’s material. The aligned flow properties and good adhesion also ensure perfect wetting of the filter medium and excellent bonding to a wide variety of substrates. This allows filters based on ceramic materials or polymers such as polyether sulphone or PVDF to be reliably potted and bonded.

The formulation of the Wevo potting resin consists of particularly pure raw materials, which are formulated in such a way that no volatile components are released. The product also combines high mechanical strength with a certain flexibility, making the material less brittle in use than a comparable epoxy resin. In addition, WEVOPUR 2082, together with the hardener WEVONAT 1000, provides excellent resistance to the cleaning and rinsing agents commonly used in water treatment systems.